What Does Jesus Mean by “Sexually Immoral?”
Jesus said in Revelation 21:8,
But as for the cowardly, the faithless, the detestable, as for murderers, the sexually immoral, sorcerers, idolaters, and all liars, their portion will be in the lake that burns with fire and sulfur, which is the second death.
While you will likely not find this verse with red colored font in your personal Bible, it is quite clear from the context that Jesus Christ is the One doing the talking when you begin reading from 21:5.
Many will attempt to argue that Jesus Himself never spoke on bestiality, homosexuality or polygamy. However, it is here in Revelation 21:8 where that argument falls apart. Jesus is all-inclusive. Rather than getting lost in an endless list, Jesus sums up all forms of sexual immorality into one category, much like a folder icon you see on the computer. He includes every form, whether physical or mental, of sexual activity outside of the bounds of a God-defined marriage under the category of sexual immorality.
Why is it that Jesus did not mention bestiality, homosexuality or polygamy?
To begin, it is blasphemous to say that God approves of groups that practice these sexual perversions. Does He love them as individuals made in His image? Yes, but He cannot and will not ever approve or condone their actions of immorality. He is Holy and we are sinners.
The reason Christ did not mention these three specific sins is actually very simple. He came to the nation of Israel and preached to the Jewish people. While there are examples of Christ interacting with Gentiles (non-Jewish people), even a quick glance at any of the four Gospels will assure you that Israel was the focus of His mission. As God’s covenant people, they were chosen to be the nation from where the Church would be born, and Christ made His message applicable to His target audience.
Bestiality, homosexuality and polygamy were not common practices among the Jewish people and possibly even non-existent in the nation of Israel during the time of Christ’s first coming. Had the nation been exposed to and even struggled with these sins in the past? Absolutely! That is why God speaks against them in the Law. However, at the time Christ came, Israel had become zealous for the Law and everything it contained. They felt they were doing such a good job at following every single command that they began to think highly of themselves and look down on others.
Israel did however struggle with adultery (John 8), perverse speech (Matthew 15:18-19), pornography (Matthew 5:27-30), and prostitution (Matthew 21:31-32). Obviously, two thousand years ago Israel could not pull up a pornographic website. However, to look with lust at a man or a woman and selfishly desire to feed your own cravings by fantasizing over your imaginations is Biblically considered pornography—when you mentally picture the act and allow it to consume and control you.
These are the sexual standards of the Bible. We can choose to live by them or not, but no matter who we are we will all bow before God and be held accountable to His standard of sexuality. God alone defines what is good, proper and holy. If you are involving yourself in any form of sexual immorality, then “I appeal to you therefore, brothers, by the mercies of God, to present your bodies as a living sacrifice, holy and acceptable to God…”(Romans 12:1).